1. Field of the Invention
The present invention relates to golf balls. More particularly, the present invention relates to multi piece golf balls having a core, a mid layer and a cover.
2. Description of the Related Art
Top concern to golf players for golf balls is their flight performances. The golf players particularly place great importance on flight distance attained upon shots with a driver. The golf players also place great importance on flight distance attained upon shots with a long iron and a middle iron.
A variety of proposals with respect to dimples in an attempt to improve flight performances have been made. U.S. Pat. No. 5,292,132 discloses a golf ball having dimples arranged with an extremely high density. U.S. Pat. No. 4,813,677 discloses a golf ball having a dimple pattern in which dimples having a great diameter and dimples having a small diameter are provided in combination. UK Patent Publication No. GB 2370996 discloses a golf ball having dimples with a great size.
Golf players also place great importance on spin performances of golf balls. Great back spin rate results in small run. For golf players, golf balls which are liable to be spun backwards are apt to be rendered to stop at a targeted position. Great side spin rate results in easily curved trajectory of the golf ball. For golf players, golf balls which are liable to be spun sidewise are apt to allow their trajectory to curve intentionally. Golf balls that are excellent in spin performances are excellent in control performances. High-class golf players particularly place great importance on control performances upon shots with a short iron.
Feeling experienced upon impact of a golf ball is also important for high-class golf players. The golf players prefer soft feel upon impact as well as light feel upon impact. The golf players also prefer feeling to allow the launch direction to be readily controlled.
In light of the flight performances, control performances and feelings, golf balls having a variety of structures have been proposed. For example, U.S. Pat. No. 6,106,415 discloses a golf ball having a core, a mid layer comprising an ionomer resin and a cover comprising polyurethane.
Covers having high elasticity are advantageous in terms of the flight performance. However, the highly elastic covers liable to deteriorate the control performance and feeling. Soft covers are advantageous in terms of the control performance. However, the soft covers are disadvantageous in terms of the flight performance. Demands from the golf players for golf balls have increasingly escalated in recent years. Highly balanced flight performances, control performances and feelings have been desired. An object of the present invention is to provide golf balls exhibiting excellent flight performances, control performances and feelings.